Holmes comes back to the flat in good spirits. He tells Watson that he has figured out that the pearls must have something to do with Major Sholto, who, he has discovered, died the same week that Miss Morstan started receiving the mysterious pearls. He figures that “Sholto’s heir” knows something about “the mystery and desires to make compensation.” Miss Morstan arrives outside the flat and the two men go down to meet her. Watson packs his heaviest walking stick and Holmes takes his revolver.
Holmes starts drawing the connection between Miss Morstan and the Sholtos. Though Holmes is expressly unemotional, he does have his moods—in general, if the case is going well, he is full of energy and vigor. The reverse is true too.
In the cab toward the Lyceum theatre, Miss Morstan explains that Major Sholto was a “very particular friend” to her father. Her father’s letters were full of allusions to the major and their time together commanding troops on the Andaman Islands. Miss Morstan presents Holmes with a “curious paper” she has found in her father’s desk.
This passage contains another mention of the Andaman Islands, which serves to conjure the sense of “otherness” and foreignness that helps to build the novella’s mystery.
Holmes examines the paper, which he says is the diagram of a building and has a small red cross drawn on it. Beside the cross, the paper reads, “the sign of the four – Jonathan Small, Mahomet Singh, Abdullah Khan, Dost Akbar.” Though he isn’t sure of the significance of the paper, Holmes tells Miss Morstan to guard it safely.
Like the mention of the Andaman Islands, the combination of the four names—one western, three eastern—is meant to unsettle the readership based on their fear of the foreign. While Doyle intended the three eastern names to be Indian, they are Arabic in origin. This is the moment that the titular “sign of the four” is introduced to the story.
Watson describes the gloom of London as they head for the theatre: “dense drizzly fog,” “mud-coloured clouds” and “misty splotches of diffused light” from lamps. He sees something “eerie and ghostlike” about all of the people that they pass. He can tell that Miss Morstan feels similarly to him; Holmes is deep in thought.
Arriving at the Lyceum theatre, the group is greeted by “a small, dark, brisk man” who instructs them to follow him. They get into another cab and head through the “foggy streets.” Watson tells Miss Morstan anecdotes about his time serving in Afghanistan.
The “foggy streets” function as a kind of metaphor for the neural processes of Holmes’ brain. His synapses are firing, attempting to apply his logical rigor to the evidence.
Eventually, the cab pulls up in a south London suburb, which Watson describes as part of the “monster tentacles which the giant city was throwing out into the country.” The group is led to a modest-looking house, and they are surprised to find the door answered by a “Hindoo” servant. He shows them in.
The monster imagery is expressly gothic, working a sense of the uncanny into the detective genre. The Hindu servant, too, is intended to surprise the reader—another link to “the East.”